[roll] Roll fuchsia [starnix] Add data/system prefix to gen tool

Without the data/system prefix android containers will not boot.

Original-Bug: 127810
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/871077
Original-Revision: d4ad0defa49d3dfdf9a328a0ba80702307a111c7
GitOrigin-RevId: c70d97a04210228ea7eede904970959286ed31ce
Change-Id: I6309f334f6341ba1b28f12ea30880c85fd77404e
diff --git a/stem b/stem
index 7208fee..20180aa 100644
--- a/stem
+++ b/stem
@@ -11,7 +11,7 @@
              githooks="integration/git-hooks"
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="6b256a22395086053c30971274b5a25466228589"/>
+             revision="d4ad0defa49d3dfdf9a328a0ba80702307a111c7"/>
   </projects>
   <hooks>
     <hook name="install-environment"